Identify the correct statement(s).
(A) In any lens, the optical centre is always at the centre of the lens.
(B) In a lens, if the curvature of its two surfaces is equal, the optical centre is at the centre of the lens.
(C) A light ray passing through the optical centre of a lens never shifts from the direction of the incident ray.
(D) A ray of light incident perpendicularly on a lens passes through its focus after refraction.
Choose the correct answer from the following given options.
Answer & explanation
Correct answer: option 4
The correct answer is Option (4) → (B) and (C) only **
(A) Incorrect — The optical centre is not necessarily at the geometric centre of the lens; its position depends on the curvature of both surfaces and the refractive index.
(B) Correct — When both surfaces of a lens have equal curvature (radii of curvature equal and opposite), the optical centre coincides with the geometric centre.
(C) Correct — A light ray passing through the optical centre of a lens passes undeviated, i.e., it does not change its direction.
(D) Incorrect — A ray incident perpendicularly on a lens passes straight through without deviation; it does not pass through the focus.
∴ Correct statements: (B) and (C)